Int J Ophthalmol, Vol. 10, No. 5, May 18, 2017 www.ijo.cn Tel:8629-82245172 8629-82210956 Email:[email protected]
·Clinical Research·
Comparison of corneal biomechanics in Sjögren’s syndrome and non-Sjögren’s syndrome dry eyes by Scheimpflug based device Qin Long1, Jing-Yi Wang1, Dong Xu2, Ying Li1 1
Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China 2 Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China Correspondence to: Ying Li. Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College,1 Shuaifuyuan Road, Beijing 100730, China. liyingpumch@ hotmail.com Received: 2016-07-29 Accepted: 2016-12-29
Abstract
● AIM: To compare the corneal biomechanics of Sjögren’s syndrome (SS) and non-SS dry eyes with Corneal Visualization Scheimpflug Technology (CorVis ST). ● METHODS: Corneal biomechanics and tear film parameters, namely the Schirmer I test value, tear film break-up time (TBUT) and corneal staining score (CSS) were detected in 34 eyes of 34 dry eye patients with SS (SSDE group) and 34 dry eye subjects without SS (NSSDE group) using CorVis ST. The differences of the above parameters between the two groups were examined, and the relationship between corneal biomechanics and tear film parameters were observed. ● RESULTS: The differences in age, sex, intraocular pressure (IOP) and central corneal thickness (CCT) were not significant between the two groups (P>0.05). The tear film parameters had significant differences between the SSDE group and NSSDE group (all P3 diopters spheric and >1 diopter cylindric error), recent contact lens use (within 1mo), diabetes and pregnancy. Ocular Examinations All subjects received a complete ophthalmic examination including measurement of best712
corrected visual acuity (BCVA), slit-lamp microscopy, fundus examination, and tear film evaluations (Schirmer I test, TBUT and CSS). TBUT and CSS were observed using slit lamp biomicroscopy by masked investigator A, and a Schirmer I test was performed more than 20min after dye staining by masked investigator B. Corneal Visualization Scheimpflug Technology Measurement Corneal biomechanical examination was conducted using CorVis ST (Type 72100, Oculus Optikgeräte GmbH, Wetzlar, Germany) more than 20min after the above-mentioned ophthalmic examinations by masked investigator C. The working mechanism of CorVis ST has been described in our previous publication and related literature. In brief, ten phasespecific parameters were recorded during the measurement: A1-time and A2-time (the length of time from the start to the first and second applanation); A1-length and A2-length (the length of the flattened cornea at the first and second applanation); A1-Velocity (A1-V) and A2-Velocity (A2-V) (the corneal velocity during the first and second applanation); highest concavity-time (HC-time) (the length of time from the start until HC is achieved); peak distance (PD, the distance between the two peaks of the cornea at HC); HC radius (the central concave curvature at HC) and deformation amplitude (DA, the maximum amplitude from the start to when HC is achieved) [19-21]. Intraocular pressure (IOP), which was calculated based on the first applanation, and central corneal thickness (CCT) were also generated during the process. Only acquisitions that showed “OK” for quality of scan (QS) were analyzed. All measurements were performed between 8 and 11 a.m. to avoid diurnal variation. No eyedrops were applied 1d before measurement. Statistical Analysis Statistical analysis was conducted using IBM SPSS 19.0 for Windows statistical software (SPSS, Chicago, IL, USA) and GraphPad Prism 5 (GraphPad Software, Inc.). Data are expressed as mean±SD. A Shaphiro-Wilk test was used to test normal distribution. Significance was determined by two-tailed unpaired Student’s t-test or Mann-Whitney U test for comparing the observed parameters of the two groups and Pearson’s correlation coefficient (r) or Spearman’s correlation coefficient (rho) for assessing the relationship between corneal biomechanics and tear film parameters according to data normality, and was accepted at P
·Clinical Research·
Comparison of corneal biomechanics in Sjögren’s syndrome and non-Sjögren’s syndrome dry eyes by Scheimpflug based device Qin Long1, Jing-Yi Wang1, Dong Xu2, Ying Li1 1
Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China 2 Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China Correspondence to: Ying Li. Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College,1 Shuaifuyuan Road, Beijing 100730, China. liyingpumch@ hotmail.com Received: 2016-07-29 Accepted: 2016-12-29
Abstract
● AIM: To compare the corneal biomechanics of Sjögren’s syndrome (SS) and non-SS dry eyes with Corneal Visualization Scheimpflug Technology (CorVis ST). ● METHODS: Corneal biomechanics and tear film parameters, namely the Schirmer I test value, tear film break-up time (TBUT) and corneal staining score (CSS) were detected in 34 eyes of 34 dry eye patients with SS (SSDE group) and 34 dry eye subjects without SS (NSSDE group) using CorVis ST. The differences of the above parameters between the two groups were examined, and the relationship between corneal biomechanics and tear film parameters were observed. ● RESULTS: The differences in age, sex, intraocular pressure (IOP) and central corneal thickness (CCT) were not significant between the two groups (P>0.05). The tear film parameters had significant differences between the SSDE group and NSSDE group (all P3 diopters spheric and >1 diopter cylindric error), recent contact lens use (within 1mo), diabetes and pregnancy. Ocular Examinations All subjects received a complete ophthalmic examination including measurement of best712
corrected visual acuity (BCVA), slit-lamp microscopy, fundus examination, and tear film evaluations (Schirmer I test, TBUT and CSS). TBUT and CSS were observed using slit lamp biomicroscopy by masked investigator A, and a Schirmer I test was performed more than 20min after dye staining by masked investigator B. Corneal Visualization Scheimpflug Technology Measurement Corneal biomechanical examination was conducted using CorVis ST (Type 72100, Oculus Optikgeräte GmbH, Wetzlar, Germany) more than 20min after the above-mentioned ophthalmic examinations by masked investigator C. The working mechanism of CorVis ST has been described in our previous publication and related literature. In brief, ten phasespecific parameters were recorded during the measurement: A1-time and A2-time (the length of time from the start to the first and second applanation); A1-length and A2-length (the length of the flattened cornea at the first and second applanation); A1-Velocity (A1-V) and A2-Velocity (A2-V) (the corneal velocity during the first and second applanation); highest concavity-time (HC-time) (the length of time from the start until HC is achieved); peak distance (PD, the distance between the two peaks of the cornea at HC); HC radius (the central concave curvature at HC) and deformation amplitude (DA, the maximum amplitude from the start to when HC is achieved) [19-21]. Intraocular pressure (IOP), which was calculated based on the first applanation, and central corneal thickness (CCT) were also generated during the process. Only acquisitions that showed “OK” for quality of scan (QS) were analyzed. All measurements were performed between 8 and 11 a.m. to avoid diurnal variation. No eyedrops were applied 1d before measurement. Statistical Analysis Statistical analysis was conducted using IBM SPSS 19.0 for Windows statistical software (SPSS, Chicago, IL, USA) and GraphPad Prism 5 (GraphPad Software, Inc.). Data are expressed as mean±SD. A Shaphiro-Wilk test was used to test normal distribution. Significance was determined by two-tailed unpaired Student’s t-test or Mann-Whitney U test for comparing the observed parameters of the two groups and Pearson’s correlation coefficient (r) or Spearman’s correlation coefficient (rho) for assessing the relationship between corneal biomechanics and tear film parameters according to data normality, and was accepted at P
